System and method for automatically feeding, inspecting and diverting tablets for continuous filling of tablet containers

ABSTRACT

A system and method for automatically feeding, inspecting and diverting tablets for continuous filling of tablet containers includes a tablet conveyor system which divides the tablets in a plurality of tablet streams for inspection by color, size and shape. Following the tablet inspection, each tablet passes through a tablet diverter which diverts the tablets to a recycle stream, reject stream or one of two bottle filling positions based upon instruction from the inspection. A bottle conveyor system is provided which feeds empty bottles into a bottle escapement mechanism which positions the empty bottles for filling. Filled bottles are moved from the bottle escapement mechanism to an exit conveyor. The entire system is computer controlled by various control mechanisms to enable the system to be fully operational without operator assistance.

This is a division of application Ser. No. 08/239,794, filed May 9,1994, now U.S. Pat. No. 5,522,512.

FIELD OF THE INVENTION

The present invention is directed to a system and method forautomatically feeding, inspecting and diverting tablets for continuousfilling of tablet containers and, in particular, a system and methodwhich is capable of sorting a continuous stream of tablets toautomatically fill a container with a predetermined number of tabletssuch as prescription pills, for direct distribution. In the case ofpharmaceuticals, the filled container is suitable for distribution tothe user or wholesaler.

BACKGROUND OF THE INVENTION

In the prior art, various methods and apparatus have been proposed toinspect a continuous stream of moving articles and divert unacceptablearticles from the moving stream. U.S. Pat. No. 3,283,896 to Jirik et al.discloses a coffee bean sorting apparatus which uses lamps to inspect acontinuous stream of coffee beans to sort undesirable coffee beans anddebris from desirable coffee beans. A deflector arm directs the coffeebeans into the appropriate bin based upon the inspection system.

U.S. Pat. Nos. 4,168,005 and 4,324,336 to Sandbank disclose a separatingapparatus which utilizes a conveyor belt, inspection system and divertervalve to separate a continuous stream of traveling articles such ascrops, clods of earth or the like.

Apparatus have also been proposed for sorting tablets or capsules. U.S.Pat. No. 5,238,124 to Cane et al. discloses an apparatus utilizingrotating combs to separate a continuous stream of traveling capsulesbased upon the capsule configuration.

U.S. Pat. No. 5,135,113 to Mayer et al. discloses a high-speed tabletsorting machine which utilizes capacitive measurement to determinetablet weight. Depending on the sensed capacitive measurement, thetablets are diverted into one of two paths to an appropriate collectionbin.

U.S. Pat. No. 5,191,741 to Jones discloses a fluidized bed bottlefilling system. In this system, tablets are transferred from bulk intosmall containers such as bottles. Typically, the filling system includesa moving bin made of a series of grooved slats which pass beneath aquantity of fluidized tablets. The grooves are further subdivided intocavities and one tablet is permitted to drop into each cavity until allof the cavities are filled. After the filled slats move from beneath thetablet bin, the tablets are ejected, collated and fed into each bottlevia transport through a manifold system.

Although prior art systems have been proposed to automatically filltablet containers, many containers are still manually filled at thepharmacy level based upon a given prescription. While this method offilling may provide an accurate and high quality prescription drugfilled container, it is tedious, time consuming and expensive.

Automatic systems such as the fluidized bed bottle filling system ofJones provide advantages in the time taken to fill a given container butare deficient in the ability to provide a filled container thatconsistently contains the correct number and type of tablets for use bya consumer.

In view of these deficiencies, a need has developed to provide anautomatic system which continuously fills tablet containers and iscapable of feeding, inspecting and diverting tablets based upon apredetermined set of parameters to provide a tablet container having theproper number and type of tablets therein.

In response to this need, the present invention provides a system andmethod for automatically feeding, inspecting and diverting tablets forcontinuous filling of tablet containers. In this manner, a prescriptioncan be automatically filled using the inventive system and method andmailed or given to a user without the need for a pharmacist.

SUMMARY OF THE INVENTION

It is a first object of the present invention to provide a system andmethod which automatically and continuously fills tablet containers fordirect distribution to a user.

It is another object of the present invention to provide a system andmethod which automatically feeds, inspects and diverts tablets duringthe filling operation to assure that the filled containers have theproper number and type of tablet therein.

Another object of the present invention is to provide a system andmethod which can inspect every tablet for size, shape and color, has nomechanical parts specific to a particular tablet, so it can handle anytablet shape.

A further object is for a system which can operate at high speed andinclude rapid changeover capability, by virtue of its use of beltsrather than tablet-specific tooling.

It is a further object of the present invention to provide a system andmethod which provides enhanced assurance of product quality, reducedoperating, maintenance, and manpower needs and the ability to producesmaller economic lot sizes which reduce product inventories and increaseresponsiveness to filled container requirements.

It is another object of the present invention to provide a system andmethod which offers a simple mechanical configuration coupled to sensingand control features which allow automatic calibration and self learningof new tablet sizes, is easily accessible for cleaning and periodicmaintenance, permits continuing operation in the event of a partialinterruption in tablet flow, has the ability to accommodate differentbottle shapes and eliminates direct operator involvement during normaloperation.

A still further object of the present invention is to provide a bottleor container filling system which permits continuous filling of acontinuous stream of discrete bottles with a continuous stream ofarticles such as tablets for pharmaceutical use, vitamins or anymaterial typically contained in bottles or containers.

Other objects and advantages of the present invention will becomeapparent as a description thereof proceeds.

In satisfaction of the foregoing objects and advantages, the presentinvention comprises a system for automatically filling bottles withtablets comprising a hopper for storing tablets, a feeder for divertingthe stored tablets into a plurality of tablet streams, and a conveyorfor continuously conveying the plurality of tablet streams from thefeeder past an inspection station. The inspection station comprises ameans for inspecting each tablet passing the inspection station bycolor, shape and size (area) and producing a first signal indicatingwhether each tablet satisfies predetermined target values, as well ascounting each tablet. A tablet diverter receives the tablets passing theinspection system, the tablet diverter including flap valves wherein theflaps divert the tablet into a stream for recycling, rejection, orbottle filling. Each flap is responsive to the first signal from theinspection station for diverting a tablet to a given stream. A bottlefilling station receives tablets satisfying predetermined target valuesvia the bottle filling stream. The bottle filling station includes abottle escapement device which positions at least a pair of emptybottles for filling, an in-feed bottle conveyor feeding a stream ofempty bottles to the bottle escapement device and an out-feed bottleconveyor receiving filled bottles from said bottle escapement device anddirecting the stream of filled bottles away for further processing suchas capping, labeling, shipping or the like. A controller regulates thefeeder, the inspection station and the tablet diverter such that tabletscan be fed automatically from the hopper to said inspection system,inspected and diverted into one of the recycle, reject or bottle fillingstreams. The controller further regulates the bottle filling system suchthat empty bottles can be continuously filled by tablets diverted tosaid bottle filling stream.

In another aspect of the invention, a method of automatically fillingbottles with tablets comprises the steps of providing a source oftablets, separating the source of tablets into a plurality of tabletstreams, feeding the plurality of tablet streams such that each tabletstream comprises a continuous stream of discrete tablets. Each discretetablet is inspected for at least one of size, color and shape. Theinspected tablets are diverted based on the inspection step into arecycle stream, reject stream or accept stream. A continuous stream ofempty bottles is provided wherein at least one empty bottle ispositioned to receive diverted tablets from the accept stream to fillthe empty bottle. The filled bottle is recovered for further processingsuch as capping, labeling, shipping or the like. The separating,feeding, inspecting, diverting, providing, positioning and recoveringsteps are controlled to automatically fill the empty bottles with apredetermined number and type of tablet.

In yet another aspect of the invention, a device is provided for fillingindividual containers traveling in a continuously moving stream with acontinuous stream of discrete items. The device includes a body having afirst opening, a first recess sized to receive the individual containersand a first chute interconnecting the first opening and the firstrecess. The body also includes a second opening, a second recess sizedto receive an individual container and a second chute interconnectingthe second opening and second recess. Means are provided on the body forconnecting the body to a drive which can rotate the body in 180°segments. The first recess and second recess are located on the body ona line that intersects a longitudinal axis thereof. The first and secondopenings are sized and the first and second chutes are configured toreceive the continuous stream of discrete items while the body isrotated in a 180° segment so that an individual container, in either thefirst or second recess, can be continually filled with discrete itemstraveling through either the first or second chute during body rotation.

Preferably, the body is cylindrical in shape with the first and secondrecesses diametrically opposed in the cylindrical body side surface. Inthis embodiment, the bottom of the body can be configured to receive thedrive for rotating the body with the top of the body having the firstand second openings therein.

More preferably, one of the openings is aligned with a longitudinal axisof the body with the other opening at least partially surrounding theopening located on the longitudinal axis.

In a preferred embodiment, the device can be used to fill individualcontainers with tablets for prescription use. However, the device can beused for any continuous stream of discrete items that can be divertedbetween the first and second openings for sequentially filling aplurality of individual containers in a continuous fashion.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference is now made to the drawings accompanying the inventionwherein:

FIG. 1 is schematic diagram showing the system components;

FIG. 2 is a schematic representation representing an inspection of onestream of traveling tablets in the inventive system;

FIG. 3 is a schematic representation of the bottle filling system of theinvention;

FIG. 4 is a schematic diagram depicting the general architecture of thefilling station control system;

FIG. 5 is a schematic diagram showing the operating states of one of thecontrol systems of the invention;

FIG. 6 is an example of a re-entrant boundary situation seen duringinspection system; and

FIG. 7 is a perspective view of an exemplary modular arrangement of theinventive system;

FIG. 8 is a cross-sectional view of an exemplary tablet diverter;

FIG. 9 is a front perspective view of a container filling device;

FIG. 10 is a cross-sectional view of the filling device of FIG. 9;

FIG. 11 is a top view of another embodiment of the container fillingdevice; and

FIG. 12 is a cross-sectional view along the line x-x of FIG. 11.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The inventive system and method is directed to an automatic tabletfilling system which enhances product quality and provides for efficientsmall lot-sized packaging. Using a simple mechanical configuration andsophisticated sensing and control, tablets can be fed from a hopperusing vibratory feeders through an inspection system. Once inspected,the tablets can be sorted for recycle, rejection or bottle filling.

The inventive system and apparatus offer advantages over other prior andesigns in the ability to accommodate different tablet types and bottlesizes without a need for changes in system set up. Other featuresinclude automatic calibration and self learning of new tablet types,elimination of direct operator involvement during normal operation andthe ability to continue bottle filling in the event of one or moretablet streams becoming unavailable.

These features result in enhanced assurance of product quality, fastbatch to batch changeovers and reduced operating costs, maintenance andmanpower needs. In addition, packaging line efficiency and utilizationis increased and smaller economic lot sizes are obtainable which reducesproduct inventories and increases responsiveness.

The inventive system and method make it possible to fill bottles with apredetermined number and type of tablets.

Although it is anticipated that the system can handle a wide range oftablet sizes, preferred tablet dimensions are as follows (These arebased on circle diameters):

Maximum tablet dimension--0.8" or 20 mm

Minimum tablet dimension--0.2" or 5 mm

Minimum tablet thickness--0.1" or 2.5 mm

Likewise, any size bottle is believed to be adaptable with the presentsystem. Preferably, 30, 75 and 120 ml bottles are used, but bottles aslarge as 250 or even 500 ml can be employed.

With reference now to FIG. 1, the inventive system is generallydesignated by the reference numeral 10 and comprises a tablet conveyorsystem 1, and inspection system 3, a tablet diverter system 5, a bottleconveyor system 7 and a filling station control 9. The tablet conveyorsystem 1, tablet diverter system 5 and bottle conveyor system 7 areidentified by the hatched rectangular areas. Each of the above-listedsystems and control will be described hereinafter under separateheadings.

Tablet Conveyor System

The tablet conveyor system 1 includes a tablet hopper 11 which can befilled using any conventional tablet source 13. The tablet hopper 11 isstainless steel and can be mounted onto a stainless framework using apivot, which enables the hopper to be pivoted from the vertical to thehorizontal for easy cleaning.

The tablet hopper 11 is used to feed a vibratory feeder 17 through fourseparate discharge ports of chutes (not shown) from the hopper gatevalve 15.

The hopper can have two low level sensors to signal when it should befilled and two high level sensors to signal when to stop filling. Thesensors are preferably a capacitive type with a plug at the sensor forremoval if required. The hopper capacity is variable depending on itssize but is preferably approximately 80 liters.

The vibratory feeder 17 produces well defined and singulated streams oftablets 21 (two for each of the four channels emanating from the hoppergate valve 15). Although any feeder can be used to accomplish thisfunction, a vibratory feeder is preferred. The feeder 17 can be astainless steel type which is mounted onto a frame using rubberanti-vibration mounts. A vibratory drive, fully enclosed, can beunderslung beneath a vibratory trackway of the feeder. The vibratorytrackway linear speed can be varied automatically for different tabletsby adjusting the vibration amplitude of the vibratory drive. Optionally,a sift mesh can be provided on the vibratory feeder which enables smalltablet fragments and/or dust to drop into a collection bin or vacuumextractor.

The four pairs of tablet streams 21 are fed to a conveyor system 23. Theconveyor system transports each of the eight streams of tablets to aninspection system 3 for sorting prior to bottle filling.

In a preferred embodiment, the conveyor system can be mounted on aframework and can include up to 4 separate or 2 paired FDA acceptablebelts, of suitable width. Seamless black PVC belts, 300 mm wide, with anFDA approved clear PVC overlay are exemplary. Easy belt changing isdesirable to facilitate easy cleaning. Each belt can be kept separate bya barrier system, so that each line can package a different tablet.Typically, the belt will mn at a speed of 200 mm/sec. but other speedsmay be used depending on system variables.

The seamless black belts can mn over a bed plate which extends beyondthe outer belt edges with its sides being turned to minimize thepossibility of tablet entrapment.

Preferably, the belt conveyor can include a rolling knife edge assemblyto control the tablet exit trajectory as the tablets leave the belt, abelt tensioner mechanism and a belt cleaning mechanism to assure thatthe belt is clean when receiving tablets. The cleaning mechanism can beany known type, for example, a cloth or a vacuum system.

By providing a plurality of separate individual belts or pairs of belts,increased flexibility and production is achieved since each belt can beserviced independently of other belts in operation.

Inspection System

Inspection system 3 is part of the quality control aspect of the tabletbottle filling system 10. Each system inspects two parallel streams oftablets as they pass on the belt to check that the tablets are of thecorrect color, shape and size and are undamaged. Damage as well as sizeis checked to assure efficacy of dose; about 10% of the tablet can bemissing before rejecting one tablet. As shown in FIG. 1, one inspectionsystem 3 is provided for each pair of parallel streams of tablets 21. Intotal, for the four pairs of parallel streams, four inspection systemsare provided.

Once an individual tablet has been inspected by the system 3, the resultof the inspection is sent to the diverter control 25 which, in turn,utilizes this information to control the tablet diverter system 5 forfilling bottles.

FIG. 2 details inspection system components. The system uses three linescan cameras: one camera 27 to provide data on shape and area and onecolor data. This camera also judges damage. The other two cameras 29provide data on the other two colors. The cameras are connected to aframestore and image pre-processing hardware 31 which extracts edge andcolor information from the scanline date. The framestores includeinterfaces to allow a monitor 33 to be connected to observe the image.The data from the image pre-processing hardware is passed to a digitalsignal processor via a first in first out buffer, and an associatedinterrupt is generated at the end of each scanline. The interrupt willbe discussed in greater detail hereinafter. The digital signal processorsub-system consists of a processor, data memory, program data memory andnon volatile memory. The code for the inspection system is stored in thenon-volatile memory and is loaded into fast program memory oninitialization. Once the sensed data has been processed by the digitalsignal processor, the results are sent to the diverter control 25 viathe communication first in first out buffers for tablet diversion.

To achieve the color sensitivity necessary to resolve the differencesbetween similar tablet shades it is necessary to have tightly definedcolor channels and carefully controlled illumination. This can beachieved by using interference bandpass filters, with each of separatecameras 27 and 29. Any 3 filter sets can be used; usually, red, greenand blue filters are used for the 3 color cameras.

The following linescan cameras are preferably used: 1×1024 element (highresolution), time delay integrated (TDI) CCD camera for size, shape andone color for camera 29, and 2×256 element (medium resolution) CCDcamera for the other two colors, cameras 27.

A beamsplitter/filter combination allows all three cameras to see thesame view simultaneously. Each camera has its own color filter, focusinglens and iris diaphragm. The magnification in the high resolutionchannel may be four times larger than in the other two channels.

The tablets in each stream pair are illuminated by two light strips fromoptical fiber light guides symmetrically disposed on each side of thevertical. This arrangement give maximum intensity of illumination on thetablets while minimizing illumination of the belt. Each pair of guidescan be powered by a single electronically controllable light source.

The image acquisition is matched to the belt speed by using an encoderassociated with the conveyor 23.

Image processing algorithms are model based with separate shape, size,and color models. Each model is learned automatically at the start of abatch as part of a TEACH procedure to be described hereinafter. Thisflexible approach allows all new tablet types to be taught with nooperator programming required.

Tablet size, shape and color are determined as follows:

Tablet area measured by counting the number of pixels in each tabletcandidate.

Tablet shape is measured by an R-theta algorithm. This works by firstcalculating the first area centroid of the tablet and then measuring theradius of the tablet relative to the center at a number of equal angularincrements. A shape template of the tablet as radius versus angle indegrees is stored in the system. An observed object (tablet) iscorrelated against the template and its matching error calculated. Theshape test is a 2 stage process:

(1) check for a high correlation between the template and the object'sR-theta profiles

(2) check for a low matching error between the correlated profiles

The color test involves looking at the color difference between thetablet and a color model learned at start of each batch by averagingover a statistically significant number of tablets during the TEACHprocedure.

The color model is both the direction (hue) and the magnitude(brightness) of the color vector in "RGB" space.

The color measurements involves averaging the brightness level of thepixels in the 3 color channels to give a single number in each channel,so processing is straightforward. Brightness limits are used to excludehighlights and shadows. This is because color measurement is inaccuratein dark and highlighted regions.

Rogue tablets can be detected by color differences, since tablets havingthe same shape but different colors are packaged. If a rogue tablet wasdetected then this might stop the line. The system configuration doesnot detect a rogue tablet (as opposed to a reject tablet) by size orshape as the object could be a broken tablet, but modifications to thesoftware are possible, and the system is not limited to thisconfiguration.

The image processing electronics hardware 31 is preferably a singleprinted circuit board integrated with the cameras and optics in a singlemodule for each feeder channel 21. The cameras and optical componentscan be pre-aligned on a jig. The modules are interchangeable and noset-up is required. A jig can then be supplied when setting up thesystem on site. Each inspection system module can have its own powersupply and light source.

The inspection system operates under the control of, and outputs itsdecisions to the diverter control 25. The decision for each tablet canbe:

accept

reject

recycle

rogue

Each inspection system 3 interacts with a tablet diverter system 5 todivert each tablet based upon the decisions rendered for each tabletinspection.

Tablet Diverter System

With reference again to FIG. 1, the tablet diverter system 5 is providedfor each of the pairs of tablet streams 21 leaving the conveyor system23 and inspection system 3. The tablet diverter system 5 includes afirst tablet diverter step I identified by the reference numeral 35which diverts the tablet based on a signal from the diverter control 25to a recycle stream 37, reject stream 39 or accept stream 41.

A second diversion is performed designated by the reference numeral 43wherein each tablet is diverted to a bottle "A" stream 45 or bottle "B"stream 47.

The streams 45 and 47 representing the pair of streams from the conveyorsystem 23 are combined by a chute 49 to produce a single feed 51 or 53to the bottle conveyor system 7. Optical passage sensors 55 are providedto detect each stream of tablets 45 or 47 for each tablet diversion stepas described below. These optical passage sensors provide tablet countverification. The primary tablet counting is done from the inspectionsystem results and these additional sensors verify that the tablets havebeen correctly sorted by the diverter mechanism. Any unanticipatedobjects seen by these sensors will be treated as an error, and thebottle rejected.

With reference again to FIG. 2, in a preferred embodiment, the tabletdiverter system 5 comprises a diverter body 57 which receives thetablets 59 in free fall off the end of the conveyor 61. Although thediverter body 57 has two sets of chutes, one for each of the two tabletstreams 21, only one stream of tablets and one chute are shown in FIG.2. The diverter body 57 provides a free fall path such that the tablets59 do not touch the sidewalls until they have been diverted.

Each chute has three mechanical flaps 63, 65 and 67, respectively, todivert the tablets 59 into the correct chute. No tablets are divertedmore than once. The flaps can be mounted on shafts with keyed ends whichengage with rotary pneumatic actuators 69 for flap operation. Thediverter body and flaps can be easily removed in the overall system forcleaning.

In operation, the pneumatically actuated mechanical flaps divert thetablets into the correct chute. This is done by the diverter control 25,whose primary function is to count and route tablets to their correctdestination on the basis of the result of inspection. The divertercontrol sorts the tablets on the basis of two decisions.

The first decision determines whether the tablet is good, should berejected or should be recycled, i.e., tablet diverter step I in FIG. 1.If rejection or recycling is required, the diverter is positionedaccordingly. That is, with reference to FIG. 2, flap 63 is positioned asshown in cross hatch to divert the tablet 59 to the recycle stream.Likewise, flap 65 can divert the tablet to the reject stream ifnecessary. If the tablet is good, it is necessary to perform a seconddecision, diverter step II in FIG. 1.

The second decision checks the availability of bottles to be filled.Once a bottle has been filled, i.e. bottle "A", and is detected in thebottle conveyor system 7, the flap 67 is switched over and the bottle"B" can be filled, providing that a bottle is available. As will bedescribed hereinafter, the full bottle is pushed out of a bottleescapement mechanism of the bottle conveyor system so that an emptybottle can be placed in the filling system. If no bottles are available,tablets on the conveyor are recycled and an error message can bereported to the filling station control 9.

Tablets going into the reject 39 or recycle 37 streams are checkedindirectly by checking whether the diverter flap position is in thecorrect position and no foreign tablets are seen to enter the bottles.

Depending on the diversion of flap 67 into bottle "A" or bottle "B", thetwo tablet stream is combined using a static funnel piece for feedinginto the bottle.

The recycle stream 37 can be directed to a collection bin or back to thetablet hopper 11, see FIG. 1. The rejected tablets can also be directedto a collection bin for proper disposal.

With reference to FIG. 8, a preferred tablet diverter body is generallydesignated by the reference numeral 57' and includes flaps 63', 65' and67'. Flap 63', shown in the operative position directs the tablets intorecycle line 37. Flap 65', shown in the inoperative position, controlsflow of tablets into the reject line 39.

Flap 67' controls tablet flow between bottle "A" stream 45 and bottle"B" stream 47. Optical passage or count verification sensors 55 areprovided in each stream 45 and 47.

The tablets flowing into either stream 45 or 47 are then combined with aparallel stream in diverter body 57' via a chute (not shown) for bottlefilling.

Bottle Conveyor System

With reference back to FIG. 1, the bottle conveyor system 7 comprises abottle source 71 which feeds bottles to the in-feed bottle conveyor 73.The in-feed bottle conveyor transfers the empty bottles to the bottleescapement mechanism 75. This mechanism is adapted to position an emptybottle to receive tablets from either of streams 51 or 53.

Once a bottle is filled, the filled bottle is removed from the bottleescapement mechanism 75 by an out-feed bottle conveyor 79. Incorrectlyfilled bottles can be diverted by the bottle diverter 81 based upon adiscrepancy between the diverter control 25 and the tablet countgenerated by the optical passage sensors 55. The bottle diverter 81 candivert the incorrectly filled bottle to a rejected bottle stream 83.Correctly filled bottles can pass through into the filled bottle stream85.

In a preferred embodiment, with reference to FIG. 3, the bottle conveyorsystem 7 can include the following:

A 3 meter long, in-feed conveyor. The in-feed conveyor system itselfcomprises of:

a 41/2" wide main in-feed slat chain conveyor

a 31/4" wide recirculating slat chain conveyor

Bottles can be deposited, standing upright, onto the main in-feedconveyor which takes bottles to a bottle escapement device under eachdiverter channel. If all the bottle escapement devices have bottlespresent, then bottles on the main in-feed conveyor that have passed allthe escapement devices will be transferred onto the recirculatingconveyor designated as recycle 74 in FIG. 1, and thence return upstreamonto the main in-feed conveyor once again.

Each tablet diverter 5 has its own separate bottle escapement mechanism75--a simple interchangeable star wheel with two positions at 180degrees. These correspond to the two bottle filling positions 51 or 53for streams 45 and 47, respectively.

With reference to FIGS. 9 and 10, the bottle escapement mechanism 75includes a starwheel body 121. Extending from the surface 122 of thebody 121 are a pair of chute structures 123 and 125. As can be seen fromFIG. 10, chute structure 123 provides communication between bottle Bstream 47 and bottle B situated in the bottle filling station or recess127. In a similar manner, chute structure 125 provides communicationbetween bottle A stream 45 and bottle A, located in bottle fillingstation 129.

The starwheel body 121 has a bore 128 which receives a spindle 131 of adrive mechanism (not shown) to rotate the starwheel as will be describedhereinbelow.

The motion of the star wheels is intermittent--the star wheel rotates by180 degrees when a bottle has been filled, this motion feeds the filledbottle out onto the bottle out-feed conveyor traveling beneath thestation. While the star wheel is rotating, the other bottle is beingfilled.

In operation, the diverter valve 67 or 67' is positioned such that thetablets accepted in the tablet converter mechanism 5 are introduced intobottle A stream 45. During filling, bottle filling station 129 ispositioned adjacent the outfeed bottle conveyor 79. Thus, when bottle Ais filled, the starwheel is rotated by 180°, this rotation drivingfilled bottle A along the outfeed bottle conveyor 79, see FIG. 1.

At the same time, once bottle A is filled, the diverter flap 67 or 67'moves to divert the flowing stream of tablets into bottle B stream 47.These tablets are directed into chute structure 123 of the starwheelbody 121 to fill bottle B positioned in bottle filling station 127. Itshould be understood that once bottle A has been filled and thestarwheel rotates to discharge bottle A into the outfeed bottle conveyor79, bottle B is rotated in the starwheel 180° while it is being filledwith tablets.

During rotation of bottle B in the starwheel, the bottle filling station129, now empty, is positioned adjacent the bottle infeed or the infeedbottle conveyor 73 to accept an empty bottle. By this arrangement,either bottle A or bottle B is receiving the continuous flow of tabletsthrough either chute structure 123 or 125. Thus, there is nointerruption in tablet feeding and the high rate of bottle filling canbe achieved.

When bottle A is being filled in bottle filling station 129, there isample time during the filling cycle for an empty bottle on the infeedbottle conveyor to be directed by a diverting flap or the like in theinfeed bottle conveyor stream to fill the bottle filling station 127before the rotation of the starwheel body 121.

For example, the star wheel will take approximately one second torotate, thus for a 100 tablets/bottle fill level, the star wheel will bestationary for approximately 7 seconds. This provides ample time foranother empty bottle to be fed into the empty filling station 129 fromthe bottle in-feed conveyor.

The drive mechanism for each star wheel is a pneumatic semi-rotaryactuator coupled to a single way indexing unit. A stop cylinder ensures180 degrees movement. Sensors detect the position of the escapementmechanism and bottles at the in-feed position.

Incorrectly filled bottles (as detected by a discrepancy between thediverter control and the diverter chute sensors) are divertedautomatically on the bottle out-feed conveyor into a holding area orpen.

With reference to FIG. 3, a representative cycle of the bottleescapement mechanism sequencing is generally designated by the referencenumeral 300 and shows a first step of bottle A being filled with tabletsfrom stream 45 exiting the tablet diverter (not shown). The starwheel121 is shown with an empty station 127. An empty bottle B is fed intostation 127 from the infeed conveyor.

Once bottle A is filled, tablets are diverted to stream 47 to fillbottle B.

The starwheel is then rotated to eject bottle A while continuing to fillbottle B in station 127.

Another empty bottle designated as bottle A is then fed into the emptystation 129 from the bottle infeed conveyor.

After bottle B has been filled, tablets are diverted to stream 45 tofill bottle A.

The starwheel is rotated again to eject bottle B along the outfeedbottle conveyor while continuing to fill bottle A during rotationthereof. The bottle filling sequence begins another cycle as representedby the recycle line 46 in FIG. 3.

With reference to FIGS. 11 and 12, an alternative bottle escapemechanism 75' is shown. In this embodiment, the starwheel body 121 hasthe chutes 123' and 125' formed therein rather than separate structuresextending from an upper surface of the starwheel body as shown in FIGS.9 and 10. In this embodiment, chute 125' has a trough 131 which extendspart way around the circumference of the body to permit continualfilling of the bottle position there below during starwheel bodyrotation.

In the embodiment shown in FIGS. 11 and 12, the bottle B would then beejected into the bottle outfeed conveyor after being filled uponrotation of the starwheel body 121'. During this rotation, bottle A inbottle filling station 129' would simultaneously rotate and begin to befilled by tablets diverted into chute 125'. Empty bottle filling station127' would then receive another empty bottle from the bottle infeedconveyor 73 to continue the bottle filling cycle.

It should be understood that the bottle escapement mechanism can beutilized for the continuous filling of continuous stream of travelingempty bottles in any application involving a continuous stream oftraveling articles. For example, vitamins or candies could be divertedbetween the starwheel chutes and to fill containers positioned in thestarwheel body openings or recesses.

Control System

The inventive system and method has a distributed control system. Thatis, the system is designed to optimize data flow between the distributedcontrol elements. With reference to FIG. 1, a controlling supervisorcomputer, preferably an IBM type PC 386 functions as the filling stationcontrol 9 which communicates via serial interfaces with a number ofcustom interface boards, each with its own CPU. The custom interfaceboards correspond to the tablet conveyor system control 19, the divertercontrol 25 and a bottle conveyor system control 87.

The filling station control 9 provides an operator terminal including avideo display unit 89 displaying information pertinent to fillingstation operations and an operator input 91 in the form of a keyboard.The filling station control performs primary control functions asfollows:

receives commands from the operator keyboard;

displays information on the screen;

coordinates the distributed controllers;

responds to detected error conditions; and

processes and stores data.

It should be understood that the diverter control 25, the bottleconveyor system 87 and the tablet conveyor system control 19 are shownin FIG. 1 controlling the overall tablet system, the bottle conveyorsystem and tablet conveyor system, respectively, identified inrectangular cross hatch.

FIG. 4 shows a more detailed schematic of the control system for theinventive system and apparatus. The diverter control 25 controls analogand digital inputs and outputs associated with the diverter flaps 63, 65and 67, the bottle escapement mechanisms 75, the vibratory feeder 17,the optical passage sensors 55 and each of the inspection systems 3monitoring the pair of tablet streams 21.

The filling station control 9 also communicates with the tablet conveyorsystem control for control of the tablet conveyor 23, the hopper gatevalve 15, the amplitude of the vibratory feeder 17 and tablet hopperlevels monitored by sensors therein. This control also indicates to thefilling station control when tablet replenishment is necessary.

Finally, the bottle conveyor control 87 controls input and outputassociated with the filling station as a whole, in particular, thebottle feed conveyors 73 and 79 and their regulating gates 78. Thesystem can be shut down by a human operator if the bottles jams. Theregulating gates 78 can be any type gate or diverter that direct bottlesinto or out of the bottle escapement mechanism, e.g. a flap or plateextending into the conveyor to catch direct bottles to a fillingstation. Alternatively, the bottle conveyors can be positioned below thefilling station to feed bottles thereto or facilitate bottle exitingtherefrom.

For each filling system, there is one inspection system, one divertermechanism and one bottle escapement mechanism for each pair of tabletstreams 21. Given that there are four pairs of tablet streams, there arefour total inspection systems, tablet diverter systems and bottleescapement mechanisms. This is represented in FIG. 1 wherein only asingle pair of tablets streams 21 is depicted passing through theinspection system 3, tablet diverter system 5 and bottle escapementmechanism 75. A single table conveyor system control 19 and bottleconveyor system control 87 are provided with the bottle filling system.

While the filling station control can be designed in any known fashionto totally automate the system 10, it may operate in the states shown inFIG. 5. Much of these states represent a certain operating state for theoverall system.

For example, the maintenance level allows a maintenance technician tocalibrate the inspection system. S/W Access (software access) permitsprogramming changes to be made by an authorized user.

In the standby mode, all moving parts of the machine are stationary andbottles in the bottle escapement outlets are empty.

The changeover state is designed to lead the operator through a linestrip-down procedure, new batch of tablet data entry and line set-up.Line strip-down entails emptying the various hoppers and bins associatedwith the system and removing and/or cleaning components prior to startup. The new batch tablet data entry permits an operate to specify theoperating parameters such as batch quantity, bottles per minute, productstrength, nominal tablet size, expiration date and PSF code for a systemran. The line set-up procedure involves installation of the componentsremoved for cleaning so that the system is ready for operation.

In the teach state, the system will learn the tablet model for thecurrent tablet to be processed. This state will be discussed in moredetail hereinbelow in conjunction with discussion of the inspectionsystem operation.

In the pause state, the system may be temporarily stopped by detectionof an error as discussed below.

In the paused state, production can be restarted by entering the mnstate. Alternatively, the system will execute a cyclestep if the clearstate is selected.

Finally, the emergency stop state, as discussed above, shuts down theentire system. Once the emergency stop loop is complete, the clear statecan be entered to begin additional sequencing.

All states allow full page viewing of an event log described hereinbelow.

The following Table identifies the states of the various components ofthe inventive system when in a given state.

                                      TABLE I                                     __________________________________________________________________________           Hopper                                                                             Vibratory                                                                           Inspection                                                                          Bottle                                                                              Diverter  Star                                         Off  State Conveyor                                                                            Conveyor                                                                            State                                                                              IS State                                                                           Wheel                                 __________________________________________________________________________    Standby                                                                              --   off   off   off   recycle                                                                            taught                                                                             empty                                                                    or not                                                                        taught                                     Changeover                                                                           --   off   off   off   recycle                                                                            taught                                                                             empty                                                                    or not                                                                        taught                                     Maintenance                                                                          --   --    --    --    --   --   --                                    Cal IS Gain                                                                          --   --    --    --    --   --   --                                    Cal IS --   --    --    --    --   --   --                                    Offset                                                                        Cal IS --   --    --    --    --   --   --                                    Position                                                                      Teach  open on    on    --    recycle                                                                            teaching                                                                           empty                                 Run    open on    on    on    operating                                                                          taught                                                                             occupied                              Paused --   off   off   off   recycle                                                                            taught                                                                             --                                    Cyclestop/                                                                           open on    on    on    operating                                                                          taught                                                                             occupied                              Clear                                                                         Pause  open off   on    on    recycle                                                                            --   --                                    E/Stop --   off   off   off   recycle                                                                            --   --                                    __________________________________________________________________________     "IS" •Means inspection system; "IS taught" •Means all ISs         taught; "IS not taught" •Means some ISs not taught; "-" •Mean     undefined; "CAL" •Means calibrate                                  

It should be understood that the calibration of the inspection systemwith regard to gain, offset and position will be discussed hereinbelow.

The filling station control also includes various error conditions tomonitor system operation. Examples of such errors include out-feedconveyor backup, out-feed conveyor full, failure of an inspectioncamera, rogue tablet, wrong count of tablet, hopper low, inspectionconveyor, or the like. Depending on the gravity of the error willdetermine whether merely a message is displayed on the operator terminal89 to indicate that scheduled maintenance must occur or the system mustbe shut down to correct the error.

The control system will also be provided with an ASCII text file writtenand updated on an internal hard disk drive thereof for maintaining ahistory log of the system operation. The history log will include atabulation of production including number of good bottles filled,bottles rejected, rate in bottles per minute, tablets rejected andtablets recycled.

The history log can also include an event log which monitors errormessages, operating state changes, operator input and the like. Finally,the history log can also include a tablet model log which records theactual model data used in the inspection system when inspecting tablets.

With reference back to FIG. 2, the inspection system functions utilizingan interrupt service routine, interrupt service routine control code andcore algorithms. Basically, the interrupt service routine receives theraw data from the line scan cameras 27 and 29 and associates it withobjects which are then passed to the control code for validation. Thecontrol code manages the foreground which can operate in a number ofmodes, as well as communicating with the diverter control 25 bymessages. When an object is passed to the control code from theinterrupt service routine, the core algorithms are used to process andvalidate the object.

In an interrupt service routine, objects pass under the cameras on abelt in two streams. The camera hardware scans the streams on a line byline basis. On completion of the scanned line, the hardware generates aninterrupt to the digital signal processor. In response to the interrupt,the digital signal processor reads a register which contains a count ofthe number of chords on the current line and reads the associated datafrom a first in first out buffer. This data contains the coordinates ofthe start of object chords and information on the color contained withinthe bounds of each of the chords.

The task of building each object from its chords is delegated to thecore algorithms This process is known as object generation and includesthe following: chord to object assignment, areas summation and colorsummation.

When a completed object is found by the interrupt service routine, it ispassed to the foreground code for further processing. If the object istoo small or too long, it is treated as an invalid object.

When an object is received by the foreground code, it is processed forcolor, size and shape. Depending on the outcome of this processing, amessage is sent to the diverter control 25. The control code alsocommunicates with the diverter control and controls the mode ofoperation of the inspection system.

The core algorithms are used by the control code for object validation.The core data supplied from the interrupt service routine is transformedinto a boundary description and then finally into a radial descriptionat uniform angles around the boundary. The color of the tablet is alsocalculated. Depending on the mode of operation, the resulting data isused for object learning, or compared against the stored reference forobject validation. Given the description of the processing stepsinvolved in the inspection system, generation of the necessary softwareis considered to be within the skill of the art.

When a line scan interrupt is generated by the hardware described above,it is serviced by the inspection system's interrupt service routine.That is, for each scanline, the following data is read:

For each line, a count of the number of chords on the current line; and

For each chord, the start and end position across the line of the chord,the sum of the red, green and blue components and the sum of area overwhich color information is obtained.

Each object description is first built up using the chords supplied bythe camera hardware. The basic principle is that if two chords onadjacent scanlines overlap in the x direction, then they are chords ofthe same object. If a chord in a scanline cannot be matched to a chordon the previous scanline, it is the beginning of a new object; a newobject in the object tablet is started. If no chord can be found on thecurrent scanline for an object that is being built, then the objectdescription is complete. Exceptions to these rules can occur for objectswhich have re-entrant boundaries to be discussed below.

Two chords overlap if at least one pixel location on the x axis iscommon to both chords. All chords which are connected together, or areconnected via another chord, form pan of the same object.

A slightly complicated case is an object which has a re-entrantboundary. An example is shown by the sideways Y in FIG. 6. When theinspection system first sees chords from the object, it appears that thechords form two different objects. The chords are marked with objectlabels 1 and 2 (say) as shown in FIG. 6. At scanline k the object stillappears to be two objects, but at scanline (k+1) the chord is connectedto both of the current objects. The new chord is marked as being a chordof object 1, and the association variable of the object 2 in the objecttable is set to 1. All the subsequent chords in the object are marked aspan of object 1. The complete set of chords is gathered together by theforeground code.

For each object started by the interrupt service routine, the followingstatistics are gathered by the interrupt service routine and saved in anobject table:

tablet area

sum of red, green and blue color components

object area over which valid color information was gathered

length of object

flags to indicate object has completed or too long

associations between object because of re-entrance

The interrupt service routine can also check for an inspection lampfailure by checking that there is always at least one chord, for theobject diverter, on each scan line. If no chords are present on a linethen a flag will be set to indicate lamp failure.

If the chord count for the line exceeds the number that can be processedbetween interrupts, then this indicates a data overload condition. Whenthis condition is detected, a flag will be set to inform the foregroundtasks.

The inspection system can be instructed to move between variousoperating states by receiving commands from the diverter control. Whilethe inspection system is not returning data messages to the divertercontrol, a periodic status message shall be sent to the divertercontrol. The main inspection lamp will be dimmed in states that do notrequire the lamp.

On termination of all states, the inspection system will return to theStandby state.

The inspection system variables such as offset, gain and position can becalibrated as follows. The calibration state is used to performcalibration on parts of the optical system. It assumes that the correctuser operation (placing of target under cameras, etc.) has beenperformed before calibration is invoked. Calibration should be performedin the correct sequence with offset done before gain. If an element of acamera gives readings which are outside expected limits, then it isassumed that this camera is defective and this information will bereturned in the calibration end message. Any pixel filtering (lone pixelsuppression) provided by the acquisition hardware must be disabledduring calibration.

The purpose of offset calibration is to offset any output from thecamera elements when no light enters the camera. The output from eachelement of the camera will be read from the framestore and averaged overseveral scan lines, the resultant value will be placed in the offsethardware and saved in non volatile memory.

The purpose of gain calibration is to normalize the output from thecamera elements when light is entering the camera. This is used tocompensate for variations in individual camera elements and inspectionlight intensity across the scan line. The output from the individualelements shall be averaged across several lines. These averages are thenused to calculate the gain correction values to be written to the gaincorrection hardware, and saved in non volatile memory.

The purpose of position calibration is to put the vision hardware in astate to assist with camera alignment. This will include turning theinspection light up. The inspection system will stay in this state untilcommanded to leave.

The inspection system also performs the teach function to learn whatparameters are to be monitored for a given tablet ran. In the teachstate, the system will learn the tablet model for the current tablet.Teaching is done in two parts: finding a valid initial object to startthe model, and then building the reference model starting from theinitial object. To locate a valid initial object, teach will take arandom start object and then try to match 2 other objects in the next 10to within 5% for size and shape. If the match fails then teach willcontinue to take random start objects until a match is found. Once avalid initial object is found teach will match a larger number ofobjects (˜25) for size, shape and color, and then add these to the modelusing a weighted averaging method if they match the model. The followinginformation will be derived in the teach state:

R-theta profile for tablet

area of tablet

color vector and matching limits in RGB space

highlight and black thresholds

The Teach state will terminate when the model has been built from thecorrect number or objects of the inspection system is requested to exitteach mode. The teach state will only mn if the system has beensuccessfully calibrated. During teach, all tablets should be recycled.Teach mode may not use every tablet to pass under the inspection systemto build the model. On termination of a successful teach operation, theR-theta profile will be rotated so that the largest vector is in thefirst location of the tablet, and the model data sent to the fillingstation control.

In addition, the teach state checks against a master record forstandards of the particular tablet being packaged, to avoid the machinecalibrating itself against an incorrect sample.

In the run state, the inspection system monitors the pair of tabletstreams based on taught parameters for bottle filling. During the runstate, tablets are checked against the model obtained from the teachstate. The result of the check and the timing information associatedwith a tablet are sent to the diverter control when the object haspassed under the inspection system. For each object the timinginformation will consist of a time stamp for the leading edge (Ts) andthe time from the trailing edge of the previous object (Tb). The typesof objects that the inspection system expects to handle are describedbelow.

Two streams of good objects For each of the objects the inspectionsystem will send a message to the diverter control declaring the objectas a valid object.

Objects whose area are too small Objects whose area is smaller than 2 mmwill be ignored by the inspection system as too small, and therefore nomessage is sent to the diverter control for these.

Input overload If the number of transitions generated in a singlescanline exceeds the number that can be processed between interrupts, orthe number of active objects exceeds the size of the object table, thenthis indicates that the inspection system has overloaded with inputdata. This condition is an exception condition and is treated as such.The diverter control will be sent a recycle message and should recycleeverything (both streams) until a valid object message is againreceived. The inspection system will empty the object table; the dataacquisition first in and first out buffer is automatically cleared atthe start of the next scanline.

Broken objects For objects which match for color but not for size orshape a reject message will be sent to the diverter control. The objectimage will be frozen in the framestore.

Rogue objects If an object does not match for color, a rogue objectmessage is sent to the diverter control. The object image will be frozenin the framestore and the system will move to the standby state to waitfor operator acknowledgement.

Overlapping objects For objects which overlap on a single stream arecycle message will be sent to the diverter control.

Objects that are too long Once an object has been detected as too long arecycle message will be sent to the diverter control.

During the life of the inspection bulb, its output spectrum will change(move towards the red end of the spectrum). While in the run state thesystem may need to adapt to this change in color by moving theacceptance criteria to track the color shift. If required this will bedone by adjusting the acceptance color vector by an average of themismatch in color detected for good objects.

During inspection, typically, the conveyor will be running at nominalspeed of 200 mm/sec. Given a scanline width of 50 microns, this resultsin a four kHz (every 250 μs) linescan interrupt rate.

With the digital processor running a 50 ns cycle, it can execute 5,000(250 μs/50 ns) instructions between interrupts. For the system tofunction, the digital signal processor must be able to read andpre-process all the data resulting from the line scan interrupt betweeninterrupts, and on average, have enough time left over to process thecompleted objects in the foreground. Initial coding of the inspectionsystem, and an assumption that on average 10 linescan pairs need to beread and processed at each interrupt, indicate that the inspectionsystem will take less than 30% of the processor's time.

The largest tablet the inspection system is expected to handle is about2 cm long. A tablet of this size will cover 400 scanlines (2 cm/50μ,).Assuming 10 transition pairs per scanline, three words of data pertransition pair and two overlapping tablets in the field of vision, themain buffer needs to be 24,000 words long (400×10×3×2).

The maximum number of active objects in the system is assumed to 32objects for each tablet stream. The threshold above which objects aredeemed to be "too long" is typically 25 mm.

As described above, the inspection system will monitor up to 4 tabletstreams and will direct the tablet diverter system via the divertercontrol to divert the tablets either to the recycle, reject, bottle "A"or bottle "B" streams. In addition, identification of a rogue tabletmight stop the system.

With reference now to FIG. 7, a perspective view of an exemplary modulartablet filling system is designated by the reference numeral 100 and isseen to include a hopper 101, vibratory feeder 103, conveyor belt 105,tablet sensing module 107, tablet diverter 109, bottle escapementmechanism 111, bottle in-feed conveyor 113 and bottle outfeed conveyor115. The bottle out-feed and in-feed conveyors 115 and 113 can serviceany number of systems. For example, FIG. 7 depicts four systems intotal. As described above, each of the system components is easilyremovable and replaceable to facilitate cleaning and set up.

There is also a feedback loop from the tablet inspection system to thevibratory feeder 103, in order to increase or decrease the amplitude ofthe vibration to the tablet hopper 101 in order to increase or decreasethe number of objects in each tablet stream.

By the inventive system, bottles can be automatically filled with apredetermined number and type of tablets which can then be directlydistributed to the ultimate end user. The inventive system provides ahigh quality assurance operation that each bottle is filled correctly toensure the safety of the end user.

As such, an invention has been disclosed in terms of preferredembodiments thereof which fulfill each and every one of the objects ofthe present invention as set forth hereinabove and provides a new andimproved automatic system for the controlled filling of bottles withtablets.

Of course, various changes, modifications and alterations from theteachings of the present invention may be contemplated by those skilledin the art without departing from the intended spirit and scope thereof.Accordingly, it is intended that the present invention only be limitedby the terms of the appended claims.

What is claimed is:
 1. A device for filling individual containers in amoving stream of containers with a continuous stream of discrete itemscomprising:a) a body having:i) a first opening, a first recess sized toreceive said container and a first chute interconnecting said firstopening and said first recess; ii) a second opening, a second recesssized to receive said container and a second chute interconnecting saidsecond opening and second recess; and b) means on said body forconnecting said body to a drive that rotates said body in 180° segments;c) wherein said first recess and said second recess are located in saidbody on a line of said body intersecting a longitudinal axis thereof; d)wherein said first and second openings are sized and said first andsecond chutes are configured to receive said continuous stream ofdiscrete items so that a container in either said first or said secondrecess can be continually filled with said discrete items travelingthrough respective said first or second chutes while said body isrotated said 180° segment.
 2. The device of claim 1 further comprising ameans for diverting flow of said continuous stream of discrete itemsbetween said first and second openings.
 3. The device of claim 1 furthercomprising a device for rotating said body in said 180° segments.
 4. Thedevice of claim 1 wherein said first opening is aligned with saidlongitudinal axis of said body and said second opening surrounds saidfirst opening and extends around a peripheral portion of said body. 5.The device of claim 1 further comprising means for delivering acontinuous stream of tablets as said discrete items.
 6. The device ofclaim 1 further comprising means for directing said individual containerinto an empty first or second recess.
 7. The device of claim 1 whereinsaid body is cylindrical in shape, said first and second recesses arediametrically opposed on a side surface of said body and said first andsecond openings are located on one end of said cylindrical body.